Vestibule air intake for jet engines



Filed Aug. 4, 1958 FIG.2 27 2 United States Patent 2,963,856 VESTIIBULE AIR INTAKE FOR JET ENGINES Alfred M. Caddell, 1318 W. Hunting Park Ave., Philadelphia 40, Pa.

Filed Aug. 4, 1958, Ser. No. 752,879

1 Claim. (Cl. 60-35.6)

Inasmuch as this application concerns a jet engine havmg adjustable vestibule means for taking in air either through the top thereof or from in front, it is applicable to pending application entitled Impulse and Reactive Tip- Driven Rotor, Serial No. 763,362, and Maximum Leverage Turbine With Compound Drive Buckets, Serial No. 820,686.

An outstanding object of this invention is to make lightweight means available on the front end of a jet engine whereby air, when taken in through the top, assists via suction the vertical rise of the aircraft described in the foregoing application.

Another object is to assist in stabilizing control of such a craft during vertical rise or descent, which control would not be possible if, due to forward suction, air were being taken in from in front.

A further and immediate need of this invention is to safeguard present-day jet engines that are mounted in winged aircraft and which are obliged to use long runways to become airborne. Some airport managements use large vacuum sweepers to clean runways before jet take-offs, but even though such precaution is taken on tearing down engines pieces of concrete, pebbles, sand and bits of glass have been found and considerable damage done. Aside from erratic flow of air and gas caused by abrasives nicking the compressor blades and adhering to the white hot turbine blades, real danger lies in the out-of-balance effect that may be caused by such damage, which effect jeopardizes safety in flight.

Jet engines are heavy air breathers, some engines requiring upwardly of 60 pounds of air per second which, roughly, is equivalent to the contents of a X 10 x 10 foot room. If air is taken in frontally the suction induced by the compressor helps move the craft forward but if taken in through the top it contributes lift to the craft of which the engine is a part. Therefore, it is essential that the direction of intake be under delicate control and as aforesaid it is also essential that dirt, etc. be kept out. This the herein described invention seeks to do.

In the drawings:

Fig. 1 is a view, looking downward, of the assembly of hinged bar members mounted as per dotted outlines in the vestibules side walls, which view is taken on the lines 1--1, Fig. 3.

Fig. 2 is an open-front view of the vestibule showing in cross section the double-walled construction thereof, a plurality of idler wheels mounted therebetween for keeping chain 13 taut, and the fully retracted hinged member assembly identified as 1 in all the figures. This view also shows the screened intake throat of the engine, an accessory section and engine shaft.

Fig. 3 is a detailed side view of the vestibule showing side walls extending forwardly in their central sections, a knife-edge construction mounted on the forward end of said side walls, the travelway for the bar member assembly to function in, idler wheels, powered sprocket and movable top plate.

Fig. 4 is a three-quarter view showing side walls extending forwardly in their central sections, the knife-edge construction on the air-entering edges of the side walls, the hinged bar member assembly in fully closed front end position, the top plate retracted and means for securing the vestibule assembly to the engine proper.

Fig. 5 shows a single hollow bar member, while Fig. 6 is a fragmentary view showing the same bar member with a flush-fitting cap secured to an end thereof. The opposite end of the member would have a similar cap.

Fig. 7 is a fragmentary view of two bar members hinged together, showing the relation of members to each other throughout the assembly.

With conventional jet engine aircraft air is, of course, taken in frontally. With a vestibule mounted on the front end of an engine, such as described, this frontal intake of air could be modified to any extent desired by moving bar assembly 1 in travelway 11 between that portion of the front end designated A and B, Fig. 3. For strictly vertical rising purposes this bar assembly may be moved to close off the front intake entirely and, by retracting the top plate entirely, permit the full intake flow of air through the top. Arrow 5, Fig. 4, indicates the take-in direction that would promote both craft stability and contribute, via suction, toward elevation of the craft of which the engine is a part.

However, if a plane were traveling down a runway with the bar assembly as shown in the Fig. 3 position, the bar members would prevent the intake of injurious matter that may lay on the runway, while clean air would enter above the members through the front, as per arrow 2, and also down through the top as per arrows 5 and 6, top plate 7 having been retracted for that purpose. As shown particularly in Fig. 3, this assembly of members becomes a means for deflecting air and any solid matter it may contain downwardly as the vestibule nose pene trates the air.

As shown in the several drawings, this assembly is comprised of a plurality of members hinged to each other between each other. Also, it will be noted that due to their construction each member is rigid in itself yet when assembled presenting an articulating wall that contributes strength for withstanding the forces imposed thereagainst by virtue of the aircraft moving forwardly at high speed.

These members are of hollow construction and their width equivalent to their depth, thus insuring their flexibility of movement in the travelway and insuring their impact strength. The hinges that tie each member to the other would be welded solidly to the respective members and extend the fully exposed length thereof, terminating at the point where the ends of the members intrude for guidance into the double-walled construction of the side walls.

As shown in Fig. 3, bar member assembly 1 rides on a layer of needle bearings 9, shown frontally in Fig. 2 and endwise in side view, Fig. 3. This bearing layer extends through the entire range of travel of the member assembly and abuts outer end wall 10. Bearing layer 9 forms the outer while chain 12 forms the inner boundaries of travelway 11. Inner wall 35 serves as a protective housing for chain 12. Bar members 1 may be secured at intervals to chain 12 by brazing means, as at 23, which permits the members to move around curves with chain 12 in travelway 11 when actuated by sprocket 13, coupled to auxiliary motor 14.

In order to maintain chain 12 in a taut condition and thus assure movement of the member assembly to any desired position in travelway 11, idler contact wheels 15, 16, 17, 18 and 19 are mounted between walls 20 which comprise the sides of the vestibule. Each of these sides is of double-walled construction to permit mounting of the aforesaid idler wheels therebetween and also to make the vestibule structure as light as possible. These walls are shown frontally in cross section in Fig. 2, in cutaway form in Fig. 3 and more complete in Fig. 4. In manufacture, it may be deemed advisable to mount the idler wheels between individual brackets, in which event the wheels would be supported by brackets 15A, 16A, 17A, 18A and 19A, respectively.

By referring to Fig. 3, it will be noted that the central area of these end walls projects forwardly into free air to form a sidewise, rounded end, V-like construction and that when moved into the position in travelway 11 as shown in this figure the bar assembly would most effectively prevent the intake of unwanted matter from the runways, while permitting the inflow of air as indicated by arrows 2, and 6. The rounded contour of these end walls permits free movement of the bar assembly in the aforesaid travelway, double-headed arrow 4, Fig. 4, indicating the functional travel of said assembly.

Knife edges 21 are mounted on the forward end of side walls 20 and project forwardly to minimize resistance to travel through air and, at the same time, lend structural strength to the side walls of the vestibule.

The vestibule's bottom plate 22 and side walls 20 encompass and extend rearwardly beyond air intake throat 34, Figs. 2, 3 and 4, of the engine to which they are removably aflixed by a plurality of bolts 24. Dotted line 25 indicates the forward end of said engine.

Top plate 7, Figs. 2, 3 and 4 rides on a layer of needle bearings 26 and is actuated by motor 27 which drives shaft 28, spur gears 29 mounted thereon meshing with plate 7 which has rack gear 30 formed in its top surface. This plate may be controlled separately from the bar member assembly, or caused to function in unison therewith.

Tube 31 is provided as a housing for the travel therethrough of chain 12 at the top of the vestibule. Shaft 32, accessory housing 33 and bell-mouth throat intake 34, while not part of this invention, are identified to establish the relation of the vestibule to an engine.

Having described my invention, I claim:

In association with a gas turbine engine having a horizontal air intake throat, a unit comprising a vestibule secured to said engine and mounted forwardly thereof and being in flow communication with said throat, said vestibule having means for controlling the directional intake of air prior to its entering said throat, a plate hav ing side ends commencing rearwardly of said intake throat and extending forwardly therefrom for supporting said vestibule, double-Walled structures defining a travel space between the walls thereof, each of said structures being mounted on a side of said plate at a right angle thereto and forwardly of said throat to comprise upright sides defining an open front and open top of said vestibule, each of said structures having a bottom wall that extends forwardly and upwardly and projects outwardly in its central area into free air and thereafter continues to the top of said structures, the most forward projection of said structures having knife edges for minimizing resistance to travel through air, said means comprising a movable plate and an auxiliary source of power having connection therewith for controlling the intake of air through said open top, a layer of bearings mounted on the tops of each of said structures for anti-frictionally supporting said plate, a second layer of anti-frictional bearings mounted on the inner side of each of said bottom walls and adhering to the contour thereof through out their lengths, said means also including an assembly of members hinged to articulate relative to each other and mounted in said travel space and establishing contact with said second layer of bearings, an auxiliary source of power having connection with said assembly for supplying motion thereto, said members being adapted to extend across said open front and, independently of the position of the plate across said open top, occupy any prescribed position in said travel space for governing the intake of air from a frontal direction into said vestibule.

References Cited in the file of this patent UNITED STATES PATENTS 2,211,491 Brooke Aug. 13, 1940 2,381,705 Vakes Aug. 7, 1945 2,508,288 Owner et al. May 16, 1950 2,568,813 Lindberg Sept. 25, 1951 FOREIGN PATENTS 476,604 Canada Aug. 28, 1951 

